OFFSET
1,1
COMMENTS
Column 5 of A183912.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..132
FORMULA
Empirical: a(n) = (1/120)*n^5 + (5/24)*n^4 + (49/24)*n^3 - (29/24)*n^2 - (461/20)*n + 43 for n>2.
Conjectures from Colin Barker, Apr 06 2018: (Start)
G.f.: x*(2 - 4*x + 19*x^2 - 18*x^3 - 10*x^4 + 11*x^5 + 5*x^6 - 4*x^7) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>7.
(End)
EXAMPLE
All solutions for n=2:
..0....0....0....2....0....1....1....0
..2....0....0....2....2....2....3....3
..2....3....0....4....4....3....4....3
..4....3....0....4....4....5....5....3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2011
STATUS
approved